Diamond bit



Sept. 16, 1941. F. E. KOEBEL ETAL DIAMOND BIT Filed April 6' 40' 4- EM? zz INVENTORS.

ATTORNEYS Patented Sept. 16, 1941 DIAMOND BIT Frank E. Koebel, Glen Ridge, and John H. Metz,

Verona,

N. J., assignors to J. K. Smit & Sons,

Inc., New York, N. Y., a corporation of New York Application April 6, 1940, Serial No. 328,258

2 Claims.

This invention relates to the diamond bit industry and is particularly directed to blast hole drilling.

" The development of diamond drilling as av means of replacing the percussion drill for blast hole work has created problems with respect to diamond bit design which have heretofore not been satisfactorily solved, and for the further economic and practical advancement of the art of diamond blast hole drilling, a diamond bit of much improved design is essential.

Various types of bits are being used for this work but in general they are designed to drill solid holes necessitating imposing tremendous pressures over the entire bit area with consequent excessive wear and high costs. As a consequence resort has been had to the thin wall coring type of bit which removes less rock and hence requires less pressure. However, such bits have inherent disadvantages in that the drill rods must be lifted to remove the core which is obtained with this type of bit. This of course increases labor costs appreciably.

One of the objects of this invention is the provision of a bit having the advantages of the thin wall coring bit so far as reduction in pressure is concerned, but with additional advantages in that we incorporate a core reducer and core breaker or crusher. It will be appreciated by those skilled in this art that such a tool will permit higher rotating speeds to be used and solid holes to be drilled at low pressure with a minimum consumption of power. It will be apparent also that drilling will be continuous inasmuch as th necessity. of stopping at intervals for the removal of 2 cores is eliminated.

In the accompanying drawing wherein we have illustrated an embodiment of our invention:

Fig. 1 is a sectional elevational view of a bit embodying our invention;

Fig. 2 is a plan view of Fig. 1; and

Fig. 3 is an exploded View of the bit of Figs. 1 and 2.

Referring to the drawing in detail: 2 designates a metal shell constituting the nose or forward end of our improved tool. This member 2 is faced with attrition elements such as commercial diamonds 4 and is integral with or rigid with the shank 6 of the tool.

Within the shank 6 and extending into the shell 2 is a core reducer 8. This is a cylindrical member faced at its forward end with attrition elements such as commercial diamonds l0. Pe-

ripheral flanges l2 are provided at the base of this core reducer, the upper face of the flanges ducer in the drilling tudinal bore I2.

, the reducer is provided when the parts Fi 1.

abutting the base of the shank E are assembled, as illustrated in The action of this core reducer 8 is to reduce the size of the core produced by the outer shell 2 which, as will be understood, leads the core reoperation, the opening l2 in the core reducer being materially smaller than the bore of the shell 2.

The wall of the core reducer 8 is provided with one or more radially extending bores I 4. We have elected to show two, but any number that may be desired or found practicable may be employed. These bores have been shown cylindrical, but this, too, is merely for purposes of illustration. The bores have been shown offset with respect to each other with respect to the longitudinal axis of the reducer. Their positioning in this regard may be varied also, as will be appreciated.

The radial bbres l4 are provided for the reception'of core crushers l6 which extend thereinto and project therefrom into the longitudinal bore I2 ofthe core reducer. These crushers may be simply cylindrical metal pieces, freely slidable in the radial bores Hi and of such a length that they project approximately half way across the longi- The inner end of each of the crushers I6 is bevelled as illustrated, the bevelled portion being faced with diamonds, as shown at Hi, to present faces extending diagonally of the axial bore l2 of the reducer 8. Retraction of the core crushers is prevented by the walls of the shank G and the shell 2.

The reducer 8 is of reduced diameter throughout part of its length, as shown at 20, to provide for the passage of flushing water between the reducer and the shell 2, while the lower part of with waterways 22 leading from the bottom of the reducer to this reduced portion.

It will be apparent from all of the foregoing that upon rotation of our improved tool the core formed by the shell 2 entering the rock is engaged, as formed, by the core reducer 8 which very materially reduces its diameter, and that the relatively small core which remains i engaged by the crushers l6 which gradually wear it away until it is completely destroyed. As a result of our construction it will be appreciated that holes can be drilled at low pressure with a minimum consumption of power. also that higher rotating speeds can be employed than heretofore, and that continuous drilling is practicable owing to the elimination of the necessity of removing cores.

It isto be understood that changes may be It will be evident made in the details of construction and arrangement of parts herein illustrated and described within the purview of our invention.

' What we claim is:

1. A bit comprising in combination, a coreproducing shell, a tool shank carrying said shell,

a hollow cylindrical core-reducer lying within said shell and shank and terminating short of the end of the shell, said shell, shank and corereducer being constructed and arranged to provide for the passage of a flushing fluid between the core reducer and the shank and shell to the forward end of the bit, and a core crusher ex- I tending radially through the wall of said reducer approximately to the center thereof so as to engage and destroy by attrition the reduced core passing through the core-reducer.

.2. A combined core reducer and core crusher for insertion into the core producing shell of a diamond bit, and comprising in combination a cylindrical member having a longitudinal bore,

and reduced in diameter throughout part of. its 7 crusher extending through the reduced portion v of the cylindrical member radially toward the axis of the said cylindrical member, the inner end of the crusher sloping toward the axis of the cylindrical member, and attrition elements set into this sloping end of the crusher.

, FRANK E. KOEBEL.

JOHN H. METZ. 

